1. Field of the Invention
The present invention relates to a magnetic field sensor and a method for manufacturing a magnetic field sensor, e.g., in the case of equipping Hall sensors in SMD housings with magnetic flux concentrators.
2. Description of the Related Art
In many applications, it is necessary or desirable to measure the magnetic field of the surroundings. Various sensors may be used. Hall sensors are frequently used, which generate an electrical voltage or an electrical current as an output signal on the basis of the Hall effect of a conductor loop permeated by a magnetic flux. These Hall sensors may be housed for large-scale mass production in surface-mounted housings (SMD housing “surface-mounted devices”). In particular, multiple Hall sensors may be integrated within a housing, for example, for differential magnetic field measurements.
Magnetic fields in very small amounts may be measured using Hall sensors. For this purpose, it may be advantageous to concentrate the magnetic flux via a specific area and conduct it through the active area of the Hall sensor. An amplification of the magnetic field via the active area of the Hall sensor may thus be achieved.
For example, a magnetic flux concentrator made of a material of high magnetic permeability is integrated into a semiconductor housing above a Hall sensor in U.S. Pat. No. 5,883,567 A. U.S. Pat. No. 7,358,724 B2 discloses a magnetic field sensor having a Hall sensor and a recess located above the Hall sensor in a semiconductor substrate, on whose side walls a layer, which concentrates the magnetic flux, made of a material of high magnetic permeability is applied.
There is therefore a demand for magnetic field sensors, using which a magnetic flux may be bundled via the active area of the Hall sensor integrated therein. A cost-effective implementation is desired in particular, which may be implemented with little additional outlay in large-scale mass production in the manufacture of the magnetic field sensors.